According to the Marriott web site, points can only be transferred to/from the account of a spouse or domestic partner (see Buy Points | Gift Points | Transfer Points | Donate Points). You could buy points or have them gifted to you, but it doesn't appear that you can have them transferred to your account from anyone other than a spouse or domestic partner.

AS I understand matters, you can only transfer between spouses/domestic partner AND only at redemption time for the shortfall. So if Mr Sagsal wishes to redeem 120,000 points for a 5 night cat 6 hotel but only has 98,000 points, Mrs Sagsal can transfer 22,000 points from her account to him. The entire process is dealt with manually via the Marriott Rewards helpline and can't be done online.

The Insiders site is the perfect place for you to share questions or inquires as you have done here. This community is full of members just like brightlybob and bejacob who are constantly helping their fellow traveler with information, recommendations and insights, photos, and news.

Additionally, in the event that you need help answering questions or would like someone to address any concerns, don't hesitate to read out to me (joshm), or lindseyh. We make up the moderation team for the forum and we're here to help.

You can indeed transfer points between you and your parents, because you are taking a trip together and sharing the points expense. I have done this numerous times when traveling with my mother. You just need to contact reservations and explain to them what you are needing to do. They will fax you (or your parents) the paperwork (yes, there is paperwork), the person donating will need to sign, then fax back, and voilà! And brightlybob is correct, it can only be done at redemption time (in conjunction with your making the reservation.)